1. Field
The present disclosure relates generally to electronic circuits, and more particularly, to an overcurrent protection circuit for a class D power amplifier.
2. Background
Power amplifiers are commonly used in various applications such as speaker drivers, headphone amplifiers, telephone line drivers, etc. Power amplifiers are categorized into different classes such as class A, class B, class AB, class G, class H, and class D. Class A, B, G, and AB amplifiers are linear amplifiers that operate in a linear region. Class D amplifiers are switch mode amplifiers that power devices operating in either deep-triode or cut-off regions. Consequently, class D amplifiers can typically achieve much higher power efficiency than linear amplifiers.
Generally, a class D amplifier may adopt a current sensor to detect output current, wherein a current minor copies an output current to another circuit by a very small proportion, and detects whether the copied current exceeds a threshold. However, when realized with an integrated circuit, the conventional current detection circuit is not very dependable, less power-efficient, and less space-efficient. Accordingly, what is needed is a current detection circuit for a class D power amplifier overcurrent protection that is robust, more power-efficient, and more space-efficient.